Characterization of precipitates in MA/ODS ferritic alloys

Mechanically alloyed, oxide dispersion strengthened (MA/ODS) ferritic alloys are attractive for fusion reactor applications because of their potential for operation at high temperatures and also because the dispersed oxide particles may provide a trap for transmutant helium. The microstructural stability of MA/ODS Fe–14 wt% Cr–3% W–0.4% Ti–0.3% Y2O3 ferritic alloys was investigated by atom probe tomography. Atom probe tomography revealed that these MA/ODS 14YWT ferritic alloys contain a high number density of nanometer scale titanium-, yttrium- and oxygen-enriched nanoclusters in the as-extruded condition. These nanoclusters were found to be extremely resistant to coarsening at temperatures of at least 1000 °C.